Laryngeal cancer
Laryngeal cancer or throat cancer is a kind of cancer that can develop in any part of the larynx. It is typically a squamous-cell carcinoma, reflecting its origin from the epithelium of the larynx.
The prognosis is affected by the location of the tumour. For the purposes of staging, the larynx is divided into three anatomical regions: the glottis (true vocal cords, anterior and posterior commissures); the supraglottis (epiglottis, arytenoids and aryepiglottic folds, and false cords); and the subglottis. Most laryngeal cancers originate in the glottis, with supraglottic and subglottic tumours being less frequent.
Laryngeal cancer may spread by: direct extension to adjacent structures, metastasis to regional cervical lymph nodes, or via the blood stream. The most common site of distant metastases is the lung. Laryngeal cancer occurred in 177,000 people in 2018, and resulted in 94,800 deaths (an increase from 76,000 deaths in 1990).[1][2] Five-year survival rates in the United States are 60.3%.[3]
Risk factors[edit]
The most important risk factor for laryngeal cancer is tobacco smoking. Death from laryngeal cancer is 20 times more likely for the heaviest smokers than for their non-smoking peers.[7] Regular and heavy consumption of alcohol, particularly alcoholic spirits, is also a significant risk factor. Using alcohol and tobacco together is an especially high risk factor and causes 89% of laryngeal cancer cases.[8][9]
Occupational exposure to environmental factors such as wood dust, paint fumes, and certain chemicals used in the metalworking, petroleum, plastics, and textile industries[10] is also believed to be a risk factor for laryngeal cancers. Infections by some forms of HPV carry some risk of laryngeal carcinoma.[11]
People with a history of head and neck cancer are known to be at higher risk (about 25%) of developing a second, separate cancer of the head, neck, or lung. This is likely due to chronic exposure to the carcinogenic effects of alcohol and tobacco. In this situation, a field change effect may occur, where the epithelial tissues start to become diffusely dysplastic with a reduced threshold for malignant change. This risk may be reduced by quitting alcohol and tobacco.
Other reported risk factors include being of low socioeconomic status, male sex, or age greater than 55 years.
Epidemiology[edit]
Incidence is five in 100,000 (12,500 new cases per year) in the US.[19] The American Cancer Society estimated that 9,510 men and women (7,700 men and 1,810 women) would be diagnosed with and 3,740 men and women would die of laryngeal cancer in 2006.
According to the GLOBOCAN 2018 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer, there were 177,422 new cases of laryngeal cancer worldwide in 2018 (1.0% of the global total.) Among worldwide cancer deaths, 94,771 (1.0%) were due to laryngeal cancer.
[20]
In 2019, it is estimated that there will be 12,410 new laryngeal cancer cases in the United States, (3.0 per 100,000).[21] The number of new cases decreases every year at a rate of 2.4%,[21] and this is believed to be related to decreased cigarette smoking in the general population.[22]
Laryngeal cancer is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that laryngeal cancer affects fewer than 200,000 people in the US.[23]